There has long existed a need for a prefabricated steel frame building structural system which can be assembled on the job site with nuts and bolts by a non-trained but mechanically inclined layman. The present invention discloses such a structural system which, in addition, requires no on site fabrication or welding, and which minimizes the number of parts necessary by making all components in the frames usable interchangeably on the left and right sides of each frame.
One of the primary objects of the present invention is to provide such a structural system which utilizes non-tapered lengths of high tensile strength, light gauge, stiffened C-channel steel stock to form the columns and beams in the frames of the building. The purpose for using such non-tapered steel stock in the columns and beams is twofold.
Firstly, it avoids the use of costly, custom designed tapered columns and/or beams typically found in steel frame buildings. This is achieved through the use of uniquely designed haunch and ridge assemblies for the column-beam and beam-beam connections which permit the use of non-tapered columns and beams according to the present invention.
Secondly, it enables the design of a structural system for a steel frame building whose height and/or width can be simply and incrementally varied, while the stress design of most of the structural components comprising the frames remains unchanged. This is achieved through designing the haunch and ridge assemblies to withstand the stress imposed by the most adverse conditions, namely a building having the smallest height and greatest width contemplated for a given range of building sizes. Hence, haunch and ridge assemblies so designed can be safely utilized for all other sizes of buildings within that range, as the height of any particular building is increased and/or its width decreased, since the loading on these assemblies decreases as the building's height is increased and/or its width is decreased within that range. Accordingly, recalling that the columns and beams are non-tapered, the only changes in the frames which are necessitated by an increase in building height and/or a decrease of building width within said range would then simply be a change in the length and/or a change in the gauge of the said steel stock used in the columns and beams in the frames. As will be appreciated, the manufacturing and inventorying of components for the frames of any building within said range is vastly reduced, resulting in major cost savings.
Another object of the present invention is to provide unique haunch and ridge assemblies which will safely and economically connect, reinforce, stiffen and transfer stress between the columns and beams and between adjacent beams, respectively, and which permit the use of non-tapered columns and beams in the frames.
A further object of the present invention is to provide haunch plates which can be used interchangeably in the left and right haunches of any frame and which can be used interchangeably in the end wall and intermediate frames, to connect, reinforce and transfer stress between their respective columns and beams.
Similarly, another object of the present invention is to provide haunch plate stiffener angles which can be used interchangeably as were the haunch plates above; and which can also be used interchangeably on both sides of the left and right haunch plates in the intermediate frames where a pair of haunch plate stiffener angles are attached to opposite sides of each left and right haunch plate. In addition, each haunch plate stiffener angle stiffens and reinforces its respective haunch plate; connects, reinforces, and transfers stress between its respective column and beam; and splices and transfers loading between the flanges of its column and beam. Each haunch plate stiffener angle can be used interchangeably because it is symmetrical about a line passing transversely through the center thereof.
A further object is to provide ridge plates which connect, reinforce, and transfer stress between their respective beams, and which can also be used interchangeably in the end wall and intermediate frames.
Another object is to provide ridge plate stiffener angles which stiffen and reinforce their respective ridge plates, and which splice and transfer stress between the flanges of their respective beams. In addition, the ridge plate stiffener angles according to the present invention can be used interchangeably in the end wall and intermediate frames, and can be used interchangeably at the top and bottom and on both sides of the ridge plates. The interchangeable nature of the ridge plate stiffener angles is achieved through their being symmetrical about a transverse line passing through the center thereof, and by the ingenious arrangement and manner of attaching each ridge plate stiffener angle to the flanges of its respective beams.
A further object of providing rake purlin angles which can be used interchangeably at the left and right sides of the end wall frames is achieved through their being symmetrical about a line passing transversely through the center thereof.
Another object of the present invention is to provide symmetrical purlin girt clips which can be used interchangeably on the left and right sides of the intermediate frames and columns due to their symmetrical nature, and which also support their respective purlins or girts during the assembly process to eliminate the need for one man to hold the purlins or girts in place while another man secures them to their respective purlin girt clips. In addition, it is an object to provide a method of making such purlin girt clips which eliminates the need for any welding during their fabrication, in order to reduce their cost.
An additional object of the present invention is to provide corner girt clips which, due to their being symmetrical about a line passing transversely through the center thereof, and due to their novel use of slotted fastening holes, can be used interchangeably at the left and right columns of the end wall frames despite the non-uniform pattern of holes which are punched in the ends of most commercially available girts.
Another object of the present invention is to provide a method for providing the framing for a steel frame building whose height and/or width can be incrementally varied within a given range without the necessity of redesigning the loading design of the haunch and ridge assemblies, and requiring at most a change in the length and/or gauge of the columns and beams used in each frame.
A further object is to provide said haunch plates, haunch plate stiffener angles, ridge plates, ridge plate stiffener angles, corner girt clips, rake purlin angles, and purlin girt clips which are assembled to their related components with nuts and bolts, rather than by being welded thereto.
Another object is to provide intermediate frames for a prefabricated, assemblable steel frame building in which the columns and beams are made from lengths of said steel stock having their webs bolted together, rather than being welded.
The foregoing description of certain objects and features of the present invention is by no means to be considered exhaustive, since these and further objects, features, advantages and characteristics will be disclosed by the following, more detailed, description of the preferred embodiments of the present invention.